Combined type-writing and computing machine.



W. WRIGHT.

COMBINED TYPE WRiTiNEi AND COMPUTING MACHINE.

1,270,479. luh utml June 25, R918.

W/newes; five/2 for:

W. WRiGHL COMBINED TYPE wnmwa AND COMPUTING MACHINE.

APPLICATION HLED AUG.I4, i917.

1,270,479. lzltmmd JImO 25, 1918.

3 SHETS-SHEET 3.

M/newes;

M QM hven/or A/for y the stop wheel 11. then the motor 12 rotates idly. 'hen. however, the stop wheel 11 rotates aside to permit a rotation of the pinwheel 10. then the friction clutch 14 forms a positive element of the driving train 13 from the motor 12 to the pin-wheel 10. The train of gearing 13 includes a shaft 15. to which the pin-wheel 10 is secured. This shaft 15 is driven by a series of gears 16 forming part of the train of gearing 13. and connects to one of the elements of the clutch 11.

The stop wheel 11 is normally held against movement. so that it prevents a rotation of the )in-u'heel 10 by the motor 12, until one of the numeral keys is depressed. At each depression of one of the numeral keys from 1 to to set one of the pins 9. mechanism is also operated to release the stop wheel 11 and thus release the pin-wheel 10. This includes heads 17. one of which provided on each of the links 6 arranged when the unit numeral key is actuated to engage and operate a universal disk 18. This umversal disk 13 is connected to operate a lever 19 against the tension of a spring 20. The lever 19 thrusts on a link 21. so as to rock a shaft 22 through the intermediary of an arm secured to the link '21. and connected to o )erate the shaft T e specific manner of rocking theshaft 2:2 is more particularly described in the patent above referred to. It is suflicient to say. however. that at the depreion of the numeral key. the shaft 22 is rocked so as to bring an open 5 ace in a disk 25 into register with one o the arms of a star wheel 26. Normally. the disk :25 is in engagement by one of the arms of the star wheel 26. and prevents a rotarv movement of the star wheel and also of a shaft :27 on which the star wheel 26 is secured. The stop wheel 11 is also secured to the shaft 27. so that the rocking of the shaft 22 controls the rotation of the pin-wheel 10. During the down stroke of the numeral kev. however. the star wheel '36 and the stop wheel 11 are not permittedvto rotate far enough to let the pinwheel 10 escape. That is to say. the arm of the star wheel 26. which escapes the first disk 25. comes into engagement with a seconddisk also secured to the rock shaft 2:? slightly beyond the disk 2-5.

At the return of the numeral key and at the-completion of the escapement movement of the carriage in the manner more particularly explained in the patent. the shaft 22 is rocked backwardly so as'to bring an openin in the disk 2? in register with the arm ofthc star wheel 26 in engagement with the disk 25. wheel 26 and the stop whee 11 to rotate one quarter of a revolution. allowing the previously set pin 9 to escape fromth stop wheel 11. The pinwheel 10 will then be This permits the star' rotated by the motor 12. until the just set pin, the setting of which released the pinwheel, comes into eiwagement with the next ttioth of the stop wheel 11. By this time then'ext arm of .;ie star wheel 26 will have com around into engagement with the first disk 25. so that the pin-wheel 10 will be again locked against rotation. The previously set pin is restored to anunset position during the rotation of the pin-wheel 10 by a cam 30 located in the path of rotation of the set pins.

Thus. this pin-wheel escapementmechanism forms an indexing or valuating mechanism which controls rotations of the shaft 15 in amounts correspondin to the values of the numeral keys actuate The indexed or valuated drives of the shaft 15 by the motor 12. under the control of the numeral keys. are transferred by a train of gearing to master wheels 31 and 32 of totalizers 33 and 34. The train of gearin includes a beveled gear 35 on the shat 15. which meshes with and drives a beveled gear 36 on a horizontal shaft 37. The shaft 37 drives. through the intermediary of meshing gears 38 and 39. a vertical shaft-l0. The vertical shaft 40 drives master wheel shafts -11 and 42 on which the master wheels 31 and 32 are splined. The connection of the 05 shaft 40 to t e master wheel shafts 41 and 42 is such that the master wheel shafts can be rotated selectively in either direction and one of the master wheel shafts can be rotated while the other is silenced. 'IZfis enables the driving of either of the totali ers 33. 34 for addition. while the other i subtracting. and also enables either f the totalizers to be active while the other /is passive.

For this purpose. a reverse aring con-' nection is provided between 1e sha t 40 and each of the master wl el shafts 41 and 42. This reverse gearin connection includes two pairs of Iiiy/fositely facing beveled gears. indicated the numbers 43.

H and 4-3. 46. These gears are loosely mounted on the shaft- 40 and the pair 43,

-14 mesh with and (I "ve a beveled gear 47 secured to the mast wheel shaft -11. while the pair of beveled gears 45. 46 mesh with and drive a beveled gear 49 secured to the master wheel shaft 42. Intermediate the pair of beveled gears 43. 44. and splined on v the shaft 40. there irovided a beveled clutch -19. which may we shifted alternatively from/an intermediate non-connecting 'position upwardly to clutching engagement with the gear 43. or downwardly to clutchiug engagement with the gear 4- Thus. the gears 43. 44 may he secured in driven relatimrwith the shaft 4" Similarly. a clutch 5 is located between the pair of beveled gears 45. 4'1. and slidingly secured to the shaft 40. so as to be shiftable from tion oz 1e is carried from such dial wheel to th t nex t higher dial wheel. This is'done bvfla tens-carrying mechanism also more flllijQaTtfSl'l'ilttNl in the patent. lie" 'tens-carrying mechanism is assisted inlitsaction by the motor 12. which is eonnc'ctie'd by gearing 'l'h'elshaftJB drives a vertical shafta'il by means ofnleshing gears 5G. The vertical shaft- 4 is connected to rotate the tenstng assisting shafts in a manner simi- -to the rotation of the master ts -12. That is to say, the assisting l rying shafts may be rotated in ,n the same direction one rotated in irection while the other is rotated 31L inftli'eopposite direction. andone rotated in either di rection while the other is passive.

This arrangement is such that the assisting shaf's will correspond in their rotation anttdiregtionof rotation with the rotation 35 ,ant'lflijrecjon of rotation of the master wheel shat'ti for the same totalizer. .The connectio| i i nel|u|es a reversible gearing for-each totalizer. For the upper total izertl this reversible gearin' includes t"pair of op- 40 .pos|tel v facin 's 56"- 5T loose on the Shaft-54, .whici mesh with and drive a beveletll geari s, secured to the tens-carrying assisting shaft The reversi'ile gearing for the lower totalq i izeji' ii l iuru ules oppositely-fadng beveled gears 59' and (it). loose on the shaft 54 and meshinghvilh to drive 'a beveled gear til secured to totla izeri-H double clutch (i2 is splin -d 5Q onjt 1e shaft 54 and interposed between the be 'vfel'ed gears 56? and 57. so as to he shift} able into mesh with either of them to'coiinec tjfeither of them in driven relation to thesh ift Similarly a double clutch ti bQais 's plined on ithe shaft 54 between the beveledgea 59 and t). and is shiftable to conneet either the beveled gear 59 or the beveled gear tjO in driven relation to the shaft 54. b othatthe change in the drive and char- 60; act'ei'a'gf; drive for the master \vlieeel' shaft and teijis carrving meclniiiis m lmay be aceo 'hplislie v 'and G2 are operated by a lever (Hroiinno'n to both-of them and having [)insQtiQQand, 66 Mgengagieg in grooves provided in clutches 52 to drive a shaft 53.

for the upper totalizei', 33.

the'assisti ng, shaft of the lower I desired, and they d conco'mitantly, the clutches 49 49 and 6'2. bnnilarly, the clutches 50 and t) are moved in unison by a lever 67, which has pins 68 and til) engaged in grooves provided in the clutches 50 and (33. While the master wheel and tens-carrying clutches are 70 moved in opposite directions. the trains of gearing from the motor and the indexing mechanism is such that their movements in unison correslmml. That is to say. the rotations of the eving assisting mechanism are such that both rotate to add or both rotate to subtract. i The principal feature of the present case includes the wheels 31. 3:5 in unison with each other.- so that they will drive step by step corresponding computing wheels in two totalizers 33, 34. This drive may be varied, as explained above, according to the typenof work it is desired to perform. In-or(le|' that; the master wheels 31. 3; may travel in uni son, they are rotatably connected to slemies 7t), 71 (l*"ig.-1i), which are loosely mounted on the..m aster wheel shafts 41:42. i The connections of thesleeves {70,11 to theatiasten wheels 31. 32 are such that themaster \vhecls;.- can slide along the shafts {I and 42 and i)t-'" rotated therelrv. and vet, rotate relatively-to the' sleeves T0, 71 which traverse tliei|iaste|-.

wheels, The sleeves T0, 71 a re connected by y a cross harIi'EL so as to-form aduplefx mastcm wheel carriage T-l i|1suring that the master .v wheels 30,31 always travelin unison.

The master V in its step-by-step movement from the t vpo-, writer carriage For this pur mse, there, is provided on the rear of the typewriter carriage 3 a raclrbar T5 (Fig. 3). which} meshes-with and drives a- .gear T6 seeuredJOB to a vertical shaft 77. The shaft T7 drives; through, a -|)i|il" of intermedianv meshinggears 78,- T9, a horizontal shaft H0. The. shaft 80 extends forward in front ofthe machine, where 81. meshing with and driving a rack bar H2. The rack bar 82 is siidingly mountedat the front of themachineby means of ways 85!. so as tov travel back and forth in unison with the typewriteq carriage 3., I In addition to being1n'ovided with a rack. the bar 82 is'pmvided with a series of openings-H, arranged at suitable intervals so as to provide meansof'athu-lnnent for pick-up or column stops 85... stops Kare provided according to the numberof majorcolumns or computim ,zones are selectively.ad ustable according to therelative jalong the bar. 82

fpositipning of thezones; desired. l'ach of 125 the] stops provided, ,wlitlr a depcnding Jug, 8ti,.,wlnel notch 87, provided. .in a shifter 83. A ,-Thea i arranged to pick up the shifter 5;

stops, are

by one, as tlie;,t vpe\vriteecan" 88, one

master wheel and the tens-can 76 means for traversing the master 80 wheel carriage. 7-} is controlled it ispl'tfl'itled with a gear J10 plurality of.these lag ia 1 :40

travels from right to left. The movement of the sto 85 with the bar 8:2, however, is from le t to right. The train of gearing from the rack 75 to the rack bar 82 is designed for this purpose. The notch 87 is lprovided with a t-dl wall 89 on its rightand side (Fig. 1), so that as eachstop 85 engages the shifter 88 for a driving movement. the engagement will be positive. On the opposite side the notch 87 is provided with a short wall 90. which will permit each sto to readily disengage from the notch an yet will catch each stop' sufliciently to prevent. accidental disengagement. due to a rebound. The shifter 88 is connected to the master wheel carriage 71. so as to traverse the same, and is yieldingly held in an active position by a spring 91.

The stops 85. when in individual engagement with the shifter 88, traverse the shifter. the master: wheel carriage 74 and the master wheels 3l and32. ste by step to the rightwith a step-by-step a vancing movement 01 the typewriter carriage 3 to the left. In this way. the master wheels 31, 32 are brought into individual driving register with the series of computing wheels of the two totalizers 33, '34. Each stop 85 corresponds to a single computing zone and to a single run ,so

of the master wheels 31, 32. 'hen the master wheels 31. reach the limit of their travel to the right. or. in other words. come into regisier -with the units computing wheels in thetotalizers 33, 34, then the master wheel carriage T4 is disconnected from the typewriter carriage 3. so as to rmit the master wheels" to be repositioned in register with the computing whe' els of highest denomination for a new run and a new computing zone. This is accomplished by a disconnector or stop 92 located in the path of an incline or slope provided on the shifter 88. 'hen this slope 93 comes into engagement with the disconnector or stop 92; theshifter 88 is depressed against the tension of the spring 91. so as to withdraw the shifter from engagement. whichever stop 5-3 happens to be in register.

T'Vhen the shifter 88 and the'master wheel carriage 74 are thus disconnected from the typewriter carriage 3. they are free to return to their starting osition. The return movement is accomplis ied by a sprin drum 94 connected tothe master wheel carriage 7 by a flexible connection 95. During the step-by-step advancing movement of the master wheel carriage Tito the right. this flexible connection 9-3 was unwound; so as to wind up the spring of the drum 94: thus;

58 to the left, their initial starting position.

By the adjustment of the pick-up stops 85 and the disoonnector 92, the period of con nection of the master wheel carria 74 with its shifter 88 can be varied. The iscoimector 92 is made adjustable for this purpose, and includes an arm 96 having a roller 97 to engage the slope or incline 93. The arm 96 1S pit-orally supported by means of a .set screw 98. which can be loosened su ficiently to. permit the arm 96 to swing up or down so as to vary the disconnecting position 0% the roller 97, and is then tightened to hold the arm 96'and the roller 97 in the selected adjusted position. In this way, the disconnector 92 may be made to release the shifter 88 sooner or later from the pick-up stops 85.

In order that the typewriter carriage"?! may not attempt to carry the master wheel carriage T4 beyond its completely returned position when the typewriter carriage is returned. there is provided a second disconnector or stop 99. which is located to engage an incline or slope 100, provided on the shifter 88 on the opposite side of the notch 87 ,to the slope or incline 93. The relation of the disconnector 99 and the slope 100 is such that the spring drum 94 is not suificiently strong to depress the shifter 88 to such a position that the high wall 89 will not reach the depending lug 86 on the 'pick-up stops 85. when the typewriter carriage 3 travels in an advancing direction.

If it is desired to disconnect the traveling master wheel carriage Tlfand thus the master wheel from the typewriter carriage 3, so that there will be no step-by-step movement of the master wheels. a manual disconnector 101 is provided. which has a pin'102 overlying the shank of the shifter 88 and arranged to depress the same to such a posik tion as to withdraw the tall wall 89 clear of the path of movementof the lugs 86 on the pick-up stops 85.

The ntilitv of this form of the invention will be readily understood when taken in connection with the above description. The pick-up stops S5 and the disco'nnector 92 are adjusted accortlin to the character of work desired. This inc odes-the numberof di t columns in the computing zones and t a magnitude of the oomputin zones. .The levers 6i and 67 may be shi ed back and forth as the work progresses. so as tohave the totalizers add or subtract orbe neutral as the need arises. This arrangement is very advantageous for hilli urposes. For instance, the items of the il may he set: down in a column and computed by one of, the mechanisms, say the gripper. the lower one being at that time inoperative. When the lower mechanism is set for "addition". and the upper mechanism is set for "sub- .raction. and the total is written down in ing mechanisms ously to said carriage to be advanced thereby. and releasing them to return repeatedly independently thereof during a single run of said carriage, and shiftable means for causing one of said Cl'05S-C0lnputing mechanisms to perform either addition or subtraction.

T. The combination with a step-by-stepfeeding carriage movable through a succe.-- sion of computing zones. of a plurality of cross-computing mechanisms, each including a traveling element. and automatic mechanism efl'cctive intermittently for connecting said traveling elements simultaneously to said carriage to be advanced thereby. and releasing them to return independently thereof during a single run of said carriage. with provisions whereby at least one of aid cross-computing mechanisms may be brought to zero independently of the other.

8. The combination with a letter-feeding carriage. of a plurality of cross-computing mechanisms. each including a traveling element, and automatic mechanism efl'ective intermittently for connecting said traveling elements simultaneously to said carriage to be advanced thereby. and releasing them to return independently thereof during a single run of said carriage. with provisions whereby any one of said cross-computing mechanisms may be brought to zero independently of any other.

9. The combination with a letter-feeding carriage, of a plurality of cross-computing mechanisms. each including a traveling element. and automatic mechanism efi'ective intermittently for connecting said traveling elements simultaneously to said carriage to be advanced'thereby. and releasing them to return independently thereof during a single run of said carriage. with provisions whereby at least one of said cross-computmay be silenced at will while others remain active.

10. The combination with av letter-feeding carriage, of a plurality of cross-com putmg mechanisms, each including a traveling element. and automatic mechanism effective intermittently for connecting said traveling elements simultaneously to said carriage to be advanced thereby, and releasing them to return independently thereof during a single run of said carriage. with provisions w ereby an one of said crosscomputing mechanisms may be silenced while others remain active.

11. The combination with a letter-feeding carriage, of-a plurality of cross-computing mechanisms. each including a travelin element, automatic mechanism effective intermittently for connecting said traveling ele ments to said carriage to be advanced thereby. and releasing them to return independently thereof, and shiftable means for causmg said cross-computing mechanisms to perform either addition or subtraction.

12. The combination withaletter-feeding carriage, of a plurality of cross-computing mechanisms. each including a traveling element, automatic mechanism efi'ective intermittentlv for connecting said traveling elements to said carriage to be advanced thereby, and releasing them to return independently thereof. and shiftable means for causing either of said cross computing mechanisms to perform eithei-vadditron or subtraction regardless of'th'e nature of the computation performed bv the other.

13. The co'mb'itiation witly'a letter-feeding carriage. of a pluralityoficross-computing pendently thereof and shiftable means to" control the activity of said computing mechanisms and the character of the computation performed thereon.

15. The cos-.rbination with aletter-feeding carriage. of a plurality of cross-computing mechanisms, each including a .traveling element. automatic mechanism effective Intermittently for connecting said travelin elements to said carriage to be advancet thereby, and releasing them to return independentlv thereof. and shiftable means to control the activity of one computing mechanism and the character of the computation performed thereon, independently of the other computing mechanism.

16. In a combined typewriting and computing machine.-the combination with numeral kevs and a letter-feeding carriage controlled thereby, of a plurality of crosscomputing mechanisms. each computing mechanism comprising a set of" computing wheels, denomination-selecting meanscontrolled by said carriage for each of said cross-computing mechanisms whereby the latter are brought into use by said carriage repeatedly during a single run of the carriage, and means for controlling the activity and direction of movement of one'compitting mechanism independently of the ot er.

17. In a combined typewriting and com- .along t-lieir shafts. i i

. nationof a series of computing heads. a,

meral keys and' r letter--feeding;marriage;

controlled"thereby. ot'a pluralilgvnof Crosscompntin'g mechanisms. each computing wheels. denomination-selectiug means controlled by said carriage for each of said cross-coonmtingi mechanisms whereby the latter are brought into use by said carriagerepeatedly during. a single run of the carriage. and manually operable means for; controlling the direction of movement of each crosscomputing. mechanism in v any zone.

18. In a computing machine. the combination with a ke \'-eontr0lle.l drive-shaft. of a series of computing heads. a master-wheel for each-of said computing heads. a shaft to which each of said master-wheels is splined.

means'to connect each of said imister-wheel shafts to said drive-shaft,- and means to move the master-wheels simultaneously along their shafts.

It In a computing machine. the combination of a series of computing heads. a

master-wheel for each of said computingheads, shafts to which said'master-wheels are splined. one of said shafts for each master-wheel. a series of keys. means controlled by said keys for rotating said mas-L ter-wheel shafts simultaneously. and mea" to inore the' master-wheels simultaneously 20. In a computing machine. the COIllbh master-wheel for each of said computing heads, shafts to which said master-\\'hcels are spliued. one 'of said shafts for each masteravheel. a series of keys. means controlled by said keys forrotating said master-wheel shafts siumltaneously in either direction. and means to more the master- Qwheels simultaneously along their shafts.

2t. In combination. a series of computin; heads mounted in single tier one below another. ,aseries of master-wheels, the typewriter carriage, and the second carriage connected to the typewriter carriage and moving said master-wheels.

:22. In combination. a series of computin; heads mounted insingle tier one belowanothcr. a series of master-wheels, the typewriter.carriagc. and the second *carriago connected to the typewriter carriage. and moving said master-wheels. and means he- .ing provided torause the master-wheel earriage. to more in theop msite direction from the typearritrr carriage.

.23. The. combination with a computing head having: a master wheel, of a deviceronnected to said master wheel. a slide con- ;neetad to said device. a hook or catch upon said slide. a typewriter carriage, a carriage adapted to move in the. opposite direction from said typewriter carriage. a ln; upon said second carriage engageable by said catch, means to release said catch. and means to return"s ai(l slide and'said master wheel qupon said catch being released.

mechanism comprising a set. of com-put ing .24.. 'lhecombination of a typewriter carmaster-wlna-ls. one for eaelicomputing head. means for eonnectin; said' master\\'heels cu lue to the typewriter carriage to more step hystep in the opposite direction from the latter, and means for automatically disconnecting said master-wheels an 1,101.- from said carriage .and returning the master-wheel and ire-connecting them to said carriage.

25. The combination with a typewriter carriage. of a second carriage. means to connect said carriages for movement in opposite directions. a set of master wheels' connected to said second carriage to more therewith. a setof computing heads to cooperate with said master wheels. a slide, and a device between said slide and said seconil carriage foroonneeting said slide thereto. 1

v 26. The combination with a typewriter carriage. of a second carriage connected thereto for movement in the opposite direction..a set of masterwheelsconnected to -.-said second carriage to moretherewith. a

, tire position of said computing heads and said nn ster-wheels. means for intermittently connecting said master-wheels to more with said carriage. and nieans'jorsilt-tiringone ofsaid master wheel shafts at will.

'28. The combination with aseries of manputing devices. each ,including'two primary elements. to wit. a. computing head and a .master-wlieel, of a master-wheel shaft for each. of said twister-wheels. a drive-shafteommou to all of said master-whirl shafts. numeral keys for controlling the rxtcnt of rotation of said common drive-shaft. a traveling arriage. means for intermittently'connet-ting one of theprimary elements of all of said computing devices so as to ell'ect a concomitant. relative movement between all of the computing heads and the masterwheels. and means for silencing any master wheel shaft at will.

29. Th combination with a plurality of eomputing devices. each comprising two primary elements, to wit, a computing head and a master-wheel, of a master-wheel shaft for each of said master-wheels, a drive-shaft common to all of said master-wheel shafts. a series of numeral keys for controllin the extent of rotation of said common riveshaft. means individual to each of said master-wheel shafts to determine the direction of drive of said master-wheel shafts indivitlually by said common drive-shaft. whereby some of said master-wheel shafts can rotate in one direction and others in the opposite direction. a traveling carriage. and means for intermittently joining one of said primary elements of all of said computing devices to move with said carriage so as to efi'ect a concomitant relative movement between all of said computing heads and their master-wheels.

30. The combination with a typewriting mechanism including a traveling carriage, of a series of computing devices. each including two primary elements. to wit, a computing head and a master-wheel, meclr anism for simultaneously connecting with and disconnecting from said carriage all of the location of the columns. and during a single run of said carriage.

33. In a computing machine. the combination with a typewriter carriage. of a plurality of computing mechanisms arran 'ed in tandem. individual actuators there or. means whereby. through the continued movement of the typewriter carriage in one direction. repeated intermittent movements maybe produced between each actuator and its corrcspomling computing mechanism, and means for silencing or reversing a'ny actuator at will.

3-1. In a computing machine. the combination with a typewriter carriage. of a plurality of computing mechanisms. individual actuators therefor. means whereby. through the continued movement of the typewriter carriageTin one direction. repeated iqgrmittent movements may be produced between each actuator and its corresponding computing mechanism. and means fol-silencing one of said computing mechanisms at will.

In a computing machine, the combination with a typewriter carriage, of a luone type of said elements of said computing rality of computing mechanisms. indivi llill devices. and means for individually controlling the activity of said computing devices independently of their connection with said carriage.

31. In a computing machine. the combination with printing mechanism and a traveling carriage for determining diflerent columns in which numbers may be printed. of computing mechanisms for accumulating the numbers printed, and means for controlling said computing mechanisms to separately accumulate debit and credit items printed in columns located at variably selected places, during a single run of said carriage.

32. In a computing machine, the combination with printing mechanism and a traveling carriage for determining different columns in which numbers may be printed, of a computing head which may accumulate credit items. a computing head which may accumulate debit items, means for varying the positions of the printed columns, and means foiacontrollin said heads to accumulate items of the ifl'erent classesin the respective computing. heads, regardless of ii'ctuato17s tl1erefor. means whereby, through the continued movement of the typewriter carriage inone direction. repeated intermittent movements may be produced by each actuator relatively to itscorresponding computing mechanism. and'means for silencing either of said computing mechanisms at will.

36. In a computing machine, the combination of a frame. a plurality of computing mechanisms fixed relatively to the frame. and each having a series of computing wheels. individual actuator shafts and actuators thereon for said wheels. each actuator shaft exclusively rotating the computing wheels of the corresponding mechanism. means whereby the actuators of the respective shafts can be caused to repeatedly engage the computing wheels of the two mechanisms'respectivelv in'a plurality of adding zones, and means for controlling the activity and direction .of movementof at-least 'one of said actuators.

. WALTER WRIGHT. Witnesses Enrm B. LIBBBY,

Jnxxn: P. Tnonxn. 

